Acid Rain
To observe how four different acids can cause acid rain: Carbonic acid, Nitrious acid, Nitric acid, and Sulfurous acid.
Grade Level: 6-8, 9-12
Formats: PDF | MS-Word

Cave Formation Age Estimation
Students will investigate actual growth rates of two flowstone formations—one from Inner Space Cavern and one from Natural Bridge Caverns. Students will graph differences in growth rates for each formation to explore variations in past climates. They will then estimate the size of each formation using a scaled photograph. Combining the formation’s size and the average growth rate, they will predict the age of the entire formation; such age estimation will provide a better understanding of the dissolution and deposition processes within a karst environment.
Grade Level: 6-8, 9-12
Formats: PDF | MS-Word

Cave Field Activity: Drip Rate Analysis (Inner Space Cavern)
Water plays a major role in cave formation. As rainwater (already acidic with a pH of 6) seeps through leaf litter and decaying matter found in soils, it mixes with carbon dioxide and becomes even more acidic. This water then flows through fractures and faults in limestone and enlarges the passages. Measuring drip rates can provide insight into how large a volume of water is making it down that particular flow path. In this activity, students will compare drip rates at several different locations throughout the cave. They will be able to observe, first hand, the heterogeneity in flow paths present in karst aquifers such as the Edwards aquifer.
Grade Level: 6-8, 9-12
Formats: PDF | MS-Word

Cave Field Activity: Drip Rate Analysis (Natural Bridge Caverns)
Water plays a major role in cave formation. As rainwater (already acidic with a pH of 6) seeps through leaf litter and decaying matter found in soils, it mixes with carbon dioxide and becomes even more acidic. This water then flows through fractures and faults in limestone and enlarges the passages. Measuring drip rates can provide insight into how large a volume of water is making it down that particular flow path. In this activity, students will compare drip rates at several different locations throughout the cave. They will be able to observe, first hand, the heterogeneity in flow paths present in karst aquifers such as the Edwards aquifer.
Grade Level: 6-8, 9-12
Formats: PDF | MS-Word

Cave Field Activity: Mapping Fractures (Inner Space Cavern)
Cave passages typically form along fractures and faults. On tours in Inner Space Cavern, students will be able to observe and measure fractures in the cave walls and ceiling. By recording fracture orientations on a cave map and later correlating them to a geologic map of Texas showing the Balcones Fault Zone, students will be able to see the role of fractures and faults in cave development.
Grade Level: 6-8, 9-12
Formats: PDF | MS-Word

Cave Field Activity: Mapping Fractures (Natural Bridge Caverns)
Cave passages typically form along fractures and faults. On tours in Natural Bridge Caverns, students will be able to observe and measure fractures in the cave walls and ceiling. By recording fracture orientations on a cave map and later correlating them to a geologic map of Texas showing the Balcones Fault zone, students will be able to see the role of fractures and faults in cave development.
Grade Level: 6-8, 9-12
Formats: PDF | MS-Word

Is Your Water Clean?
Over 2 million people rely on groundwater from karst aquifers in central Texas. Due to the high porosity and permeability of karst landscapes, inputs such as rain, streams, and rivers influence groundwater quality. In this lab, students will be able to compare the water quality of rainwater, cave water, tap water, and river water. This lesson involves students testing samples of water from different sources for pollutants and discussing the possible sources of these pollutants.
Grade Level: 9-12
Formats: PDF | MS-Word